title: Rapid in vitro assembly of Caulobacter crescentus FtsZ protein at pH 6.5 and 7.2.
abstract: FtsZ from most bacteria assembles rapidly in vitro, reaching a steady-state plateau in 5-10 s after addition of GTP. A recent study used a novel dynamic light-scattering technique to assay the assembly of FtsZ from Caulobacter crescentus (CcFtsZ) and reported that assembly required 10 min, ∼100 times slower than for related bacteria. Previous studies had indicated normal, rapid assembly of CcFtsZ. We have reinvestigated the assembly kinetics using a mutant L72W, where assembly of subunits into protofilaments results in a significant increase in tryptophan fluorescence. We found that assembly reached a plateau in 5-10 s and showed no change in the following 10 min. This was confirmed by 90° light scattering and negative-stain electron microscopy. The very slow kinetics in the dynamic light-scattering study may be related to a refractory state induced when the FtsZ protein is stored without nucleotide, a phenomenon that we had observed in a previous study of EcFtsZ. We conclude that CcFtsZ is not an outlier, but shows rapid assembly kinetics similar to FtsZ from related bacteria.
authors.affiliation: Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27701-3709, USA.
authors.forename: Sara L
authors.initials: SL
authors.lastname: Milam
authors.forename: Harold P
authors.initials: HP
authors.lastname: Erickson
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism* / Q000648:ultrastructure; D016935:Caulobacter crescentus / Q000187:drug effects / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism* / Q000648:ultrastructure; D005453:Fluorescence; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D006868:Hydrolysis / Q000187:drug effects; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D016624:Negative Staining; D012542:Scattering, Radiation
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases; D008274:Magnesium
keywords: Bacteria; Cell Division; Electron Microscopy (EM); Fluorescence; GTPase; Tubulin